Pressure effect on the microphase separation of diblock copolymer melts studied by dynamic density functional theory based on equation of state

摘要

Pressure effect on the microphase separation of diblock copolymer melts was investigated by dynamic density functional theory based on the equation of state (EOS-based DDFT). The results show the corresponding counterparts in the experiment. With the increase of pressure, all of the phase regions corresponding to the different ordered morphologies become narrower. However, the pressure dependence of the order-disorder transition temperature (ToDT) lies on the symmetry of the diblock copolymer. In the very non-symmetrical case with f being small, Tour decreases with the increase of pressure, while in the symmetrical case when f=0.5, ToDT increases with increasing pressure. Moreover, the increase in the total bead number of system at the ODT is found to be in good accordance with the experimental results, specifically, there is an increase in the volume accompanying with the transition from the ordered to disordered state. Contrary to the temperature, the pressure does not influence the starting time and the duration of microphase separation.